In the field of work machines, particularly those machines which perform digging or loading functions such as excavators, backhoe loaders, and wheel loaders, the work implements are generally manually controlled with various operator controls in addition to other machine function controls. The manual control system often includes foot pedals as well as hand operated levers. There are several areas in which these types of implement control schemes can be improved to alleviate operator stress and fatigue resulting from the manipulation of multiple levers and foot pedals. For example, a machine operator is required to manipulate and coordinate the multitude of control levers and foot pedals proficiently. To become productive, an inexperienced operator requires a long training period to become familiar with the controls and associated functions.
Some manufacturers recognize the disadvantages of having too many control levers and have adopted multifunctional control levers as the norm. A multifunctional control lever is an extremely desirable mechanism particularly for controlling lift and tilt functions on a machine having an implement such as a blade or bucket attached to lift linkage.
The difficulties encountered with some multifunctional control levers, as well as some single function control levers, is the consistent repeatability of the control lever returning to the center or neutral position when the operator releases his or her input from the lever. If the control lever does not consistently return to the center or neutral position, the operator may experience unwanted drift or movement of the linkage or implement. Having the control lever consistently return to center is critical for accurate positioning of the linkage and attached implement as well as for providing a reliable reference point for the operator.
Additionally, it is desirable to have a multifunctional control lever that not only consistently returns to the center position but also provides some resistive feedback to the operator. Furthermore, it is also desirable to have a multifunctional control lever that provides at least one detent position for controlling a machine function. Still further, it desirable to have a control lever that is easily preset to the center or neutral position before installation on a machine and is readily adjustable while installed on the machine.
The present invention is directed to overcoming one or more of the problems set forth above.